Field
The disclosed and claimed concept relates generally to electrical connection equipment and, more particularly, to a bus bar apparatus that enables line conductors at a relatively higher temperature to be connected with circuit interrupters having a relatively lower maximum temperature limit.
Related Art
Electrical distribution equipment is well known in the related art. For instance, electrical wires that extend from one location to another often are connected with circuit interruption devices such as circuit breakers, switches, fuses, and the like without limitation. The electrical wires themselves can be supported in any of a variety of fashions between the two points. One exemplary support methodology is to run the electrical wire through conduit, although the wires typically can be operated only at a relatively modest temperature since the conduit completely encloses the electrical wire therein and thus generally prevents any direct ambient cooling of the wire. Another exemplary support is a cable tray that typically is suspended from a ceiling or protrudes from a wall and that has an open tray within which the electrical wires are disposed when being run between one location and another. Electrical wires in cable trays typically can be operated at relatively higher temperatures due to the ambient cooling effect of the air that is contact with the wires as they lay in the cable tray.
For one electrical wire to be operable at a relatively higher temperature than another electrical wire, the electrical wire must employ insulation that is rated for operation at the relatively higher temperature. For example, certain electrical wire may be rated for operation at a temperature of 90° C. whereas other electrical wire may be rated for operation at temperatures no higher than 75° C. The electrical wire rated for 90° C. typically will be more costly than the wire of the same size that is rated only for 75° C. On the other hand, the electrical wire that is rated at 90° C. will be capable of operation at a higher ampacity, i.e., at a higher current carrying level, than the wire rated only for 75° C., even if the two wires are of the same wire gauge. Depending upon the particular current-carrying needs of the given application, therefore, it has been known to employ, in appropriate circumstances, a single run of 90° C. wire to be operated at a relatively higher ampacity in place of, for example, two runs of 75° C. wire that would have been operated at a relatively lower ampacity as long as the single run of 90° C. wire can meet the current-carrying requirements of the given application.
It is also understood, however, that certain electrical components such as circuit interrupters and the like are typically permitted to be connected with electrical conductive elements that are at most only of a given temperature, such as 75° C. Thus, while the running of a single 90° C. wire may be more cost effective than running two runs of 75° C. wire, the 90° C. wire cannot be directly connected with an electrical component such as a circuit interrupter because the relatively higher temperature might undesirably increase the temperature of the circuit interrupter, thereby causing it to operate in an erratic and unpredictable fashion, which is undesirable. A run of 90° C. wire thus cannot be specified for use in a given application if the wire is to be connected with a circuit interrupter or other device than can only be connected with electrical conductors that are at most only 75° C. Further difficulty is encountered if an electrical contractor failed to realize that a run of wire was to be connected with a circuit interrupter and therefore erroneously specified the installation of a run of 90° C. wire. In such a situation, the technician desirably would detect the use of 90° C. wire prior to connecting it with the circuit interrupter, thereby avoiding problems with the installation, but this often may occur only after the 90° C. run of wire has already been installed. In such a situation, it is typically necessary to remove the 90° C. wire and replaced it with 75° C. wire, likely multiple runs, or take other remedial action, at considerable additional expense. It thus would be desirable to provide an improved system that overcomes these and other shortcomings known in the relevant art.